Renal transplantation is the therapeutic modality of choice for patients with end-stage renal disease (ESRD) from a variety of causes.[1] However, the transplantation of the allografts entails considerable risks to the recipients, emanating mostly from life-long use of immunosuppressive agents. One of the major risks includes an increased predisposition to infections in the transplant recipients.[2] These infections may be caused by a variety of infective organisms including bacteria, viruses, fungi, and parasitic agents and involve an equally variable number of body tissues, including the graft itself.[2]Parasitic diseases are not uncommonly reported in renal transplant recipients, especially from developing countries. The parasites can involve a variety of organs, including the native kidneys of renal transplant recipients. One of the parasitic zoonosis in tropical regions rarely involving the kidneys is the echinococcosis (hydatidosis).[345678] Isolated renal hydatidosis is rare, and similar occurrence in renal transplant patients is further rarer. The only previous case in published literature was reported from Turkiye by Cavdar et al.[9] The current case report by Bhat et al.[10] represents, to the best of our knowledge, the second case in the world literature. There are some interesting similarities and other contrasts between the two cases. Both affected middle-aged male patients, and both cases involved the native rather than the transplanted kidneys of the renal transplant recipients. In both cases, there was no evidence of the parasitic infection at the time of transplantation.[910] The present case, however, presented one year earlier (one year after transplantation) than the case reported by Cavdar et al., and the size of the lesion was also larger. As a result, the lesion was symptomatic and palpable in the present case as opposed to the previously reported case. The authors attribute this occurrence to the use of immunosuppressants in the patient. However, it is difficult to establish the cause and effect relationship on the basis of just one case. Similarly, the pathogenesis and risk factors cannot be determined from the study of just a single case.The authors of the present report deserve compliments on bringing forth an interesting case with some learning points for relevant health care professionals involved in the care of the renal transplant patients. Hydatid disease should be considered in the differential diagnosis of any cystic or cystic-cum-solid lesions of native or transplanted kidneys in renal transplant recipients, especially in endemic areas.[9] Pre-operative diagnosis is possible, as in this case, with a combination of serology, ultrasound, CT scanning and clinical data and a high index of suspicion.[10] Medical treatment alone in transplant setting appears to be ineffective, as in the present case, and aggressive approach needs to be taken. The case is also unique in that it presented with spontaneous rupture with gross hydatiduria and a rapid increase in size. The role of the immunosuppressants in predisposing or causing aggressive growth of the lesion is at best speculative.There are a few omissions in the present case. No source of the allograft kidney is given as is the information on immunosuppressive regimen used. These may represent a risk factor for the development of hydatidosis of the kidney. There is also no information on the follow-up of the patient, as sometimes hydatid disease can recur, often in other sites, long after primary nephrectomy.There is little information on the natural history of the disease in transplant setting. There is no follow-up data in both the reported cases in the literature.[910] There is also scanty evidence for the optimal management of the disease in this setting. The patient in the case report of Cavdar et al.[9] underwent native nephrectomy straight away but the latter option was refused by the patient in the current case. As a result, the patient presented with a larger and ruptured lesion 3 years later. It seems that albendazole and the puncture, aspiration, instillation, and re-aspiration (PAIR) strategy did not work in the transplant setting. The optimal duration of chemotherapy is also not known in transplant patients.In conclusion, the current case highlights the need to consider hydatid disease in the differential diagnosis of cystic or cystic-cum-solid lesions of the native or transplanted kidneys in renal transplant patients. The case also underscores the need for an aggressive approach for the treatment of the disease in this setting as a delay can lead to complications such as rupture.